Distributed control of electric power grids

Abstract

A method for determining power output levels of a plurality of nodes in an electric power system includes receiving, at a first node of the plurality of nodes, voltage information and multipliers of all neighboring nodes of the first node within the electric power system, determining, by the first node, a local power generation and a local voltage using the voltage information and the multipliers of the neighboring nodes and distributing the local power generation and the local voltage to the neighboring nodes, determining, by the first node, an estimated voltage of each of the neighboring nodes and distributing the estimated voltage to each of the neighboring nodes, and updating, by the first node, a local multiplier using the voltage information received from the neighboring nodes and the estimated voltage of each of the neighboring nodes determined by the node.

What is claimed is: 
     
       1. A method of controlling a first power generating node of a plurality of power generating nodes in an electric power system comprising:
 receiving, at the first power generating node of the plurality of power generating nodes, voltage information and Lagrangian multipliers of all neighboring power generating nodes of the first power generating node within the electric power system; 
 controlling the first power generating node to output an actual local power and an actual local voltage determined using the voltage information and the Lagrangian multipliers of the neighboring power generating nodes received by the first power generating node and distributing local voltage information about the actual local power and the actual local voltage output by the first power generating node to each of the neighboring power generating nodes; 
 determining, by the first power generating node, an estimated voltage of each of the neighboring power generating nodes; and 
 updating, by the first power generating node, a local Lagrangian multiplier using the voltage information received from the neighboring power generating nodes and the estimated voltage of each of the neighboring power generating nodes determined by the first power generating node and distributing the local Lagrangian multiplier to each of the neighboring power generating nodes, 
 wherein each of the Lagrangian multipliers of the neighboring power generating nodes reflects voltage information received by a respective one of the neighboring power generating nodes from neighboring power generating nodes thereof and an estimated voltage of each of the neighboring power generating nodes of the respective node determined by the respective node. 
 
     
     
       2. The method of  claim 1 , performed by each node of the plurality of power generating nodes. 
     
     
       3. The method of  claim 1 , iteratively performed by the first power generating node, the method further comprising evaluating a stopping criteria after updating the local Lagrangian multiplier. 
     
     
       4. The method of  claim 1 , implemented as a fully distributed system wherein each of the plurality of power generating nodes communicates directly with all of its neighboring power generating nodes to distribute respective local voltage information and a respective local Lagrangian multiplier. 
     
     
       5. The method of  claim 1 , further comprising:
 distributing, by the first power generating node, the estimated voltage of each of the neighboring power generating nodes determined by the first power generating node to each of the neighboring power generating nodes. 
 
     
     
       6. A computer program product for controlling a first power generating node in an electric power system, the computer program product comprising a non-transitory computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to perform a method comprising:
 receiving, at the first power generating node of the plurality of power generating nodes, voltage information and Lagrangian multipliers of all neighboring power generating nodes of the first power generating node within the electric power system; 
 controlling the first power generating node to output an actual local power and an actual local voltage determined using the voltage information and the Lagrangian multipliers of the neighboring power generating nodes received by the first power generating node and distributing local voltage information about the actual local power and the actual local voltage output by the first power generating node to each of the neighboring power generating nodes; 
 determining, by the first power generating node, an estimated voltage of each of the neighboring power generating nodes; and 
 updating, by the first power generating node, a local Lagrangian multiplier using the voltage information received from the neighboring power generating nodes and the estimated voltage of each of the neighboring power generating nodes determined by the first power generating node and distributing the local Lagrangian multiplier to each of the neighboring power generating nodes, 
 wherein each of the Lagrangian multipliers of the neighboring power generating nodes reflects voltage information received by a respective one of the neighboring power generating nodes from neighboring power generating nodes thereof and an estimated voltage of each of the neighboring power generating nodes of the respective node determined by the respective node. 
 
     
     
       7. The computer program product of  claim 6 , performed by each node of the plurality of power generating nodes. 
     
     
       8. The computer program product of  claim 6 , iteratively performed by the first power generating node, the method further comprising evaluating a stopping criteria after updating the local Lagrangian multiplier. 
     
     
       9. The computer program product of  claim 6 , implemented as a fully distributed system wherein each of the plurality of power generating nodes communicates directly with all of its neighboring power generating nodes to distribute respective local voltage information and a respective local Lagrangian multiplier. 
     
     
       10. The computer program product of  claim 6 , further comprising:
 distributing, by the first power generating node, the estimated voltage of each of the neighboring power generating nodes determined by the first power generating node to each of the neighboring power generating nodes. 
 
     
     
       11. A generator in an electric power system configured to control a power output level comprising:
 a computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the generator to: 
 receive, from at least one neighboring generator within the electric power system, voltage information and Lagrangian multipliers; 
 outputting a local power and a local voltage determined using the voltage information and the Lagrangian multipliers of the at least one neighboring generator received from the at least one neighboring generator and distributing local voltage information about the local power generation and the local voltage to the at least one neighboring generator; 
 determine an estimated voltage of the at least one neighboring generator and distributing the estimated voltage to the at least one neighboring generator; and 
 update a local Lagrangian multiplier using the voltage information received from the at least one neighboring generator and the estimated voltage of the at least one neighboring generator determined by the generator and distributing the local Lagrangian multiplier to the at least one neighboring generator, 
 wherein each of the Lagrangian multipliers of the at least one neighboring generator reflects voltage information received by a respective one of the at least one neighboring generator from neighboring generators thereof and an estimated voltage of each of the neighboring generators of the respective neighboring generator determined by the respective neighboring generator. 
 
     
     
       12. The generator of  claim 11 , iteratively executing the program of instructions and further comprising evaluating a stopping criteria after updating the local Lagrangian multiplier. 
     
     
       13. The generator of  claim 12 , further comprising a communication module configured for two-way communication with the at least one neighboring generator. 
     
     
       14. The generator of  claim 11 , further comprising a communication module distributing the estimated voltage and the local Lagrangian multiplier to the at least one neighboring generator.